TIME HISTORY ANALYSIS OF BUILDING STRUCTURES WITH WATER TANK AS PASSIVE TUNED MASS DAMPER

Abstract

An earthquake is a natural phenomenon. Depending upon the intensity, itmay cause damageto life and property. Engineering community is striving hard to innovate different methods that can provide a solution to minimize this damage. The idea of seismic response control of the structures by using TMD’s is considered for this study. A tuned mass damper (TMD) is a device consisting of a mass, a spring, and a damper that is attached to a structure in order to reduce the dynamic response of the structure. The frequency of the damper is tuned to a particular structural frequency so that when that frequency is excited, the damper will resonate out of phase with the structural motion. Energy is dissipated by the damper inertia force acting on the structure. Water tanks are integral part of all buildings and they impart large dead load on the structure. This additional mass can be utilized as TMD to absorb the extra energy imparted on the structure during earthquakes.The main objective of this project is to find the response reduction of structures subjected to various earthquake data’s using different mass ratios. Analysis is carried for 5 storied and 10 storied buildings with and without water tanksand for different mass ratios varying from 5% to 25%.Water tank is placed at center and extreme corners of the building and columns of the tank with varying heights i.e., 1m, 2m, 3m and 3.5m are considered. 3 types of earthquake data(El Centro, N.Palm and Uttarkashi) are used for this study. Time history analysis is performed using SAP software. Results showed that tuning the parameters of water tank, it can be used as passive TMD to reduce the seismic response. Majority of the cases proved that results are appreciable when water tank is placed at center of the building, for columns of 3m height and 20% mass ratio.